Disruptive Behavior Disorders (DBDs) affect a substantial number of young children, have lifelong implications if left untreated, and represent the most common presenting problem to community mental health centers. Evidence-based treatments (EBTs) are available for treating DBDs including Parent-Child Interaction Therapy (PCIT). Despite EBTs' potential to help children and families, they have primarily remained in university settings. Recognized field leaders have expressed concern over the discrepancy between treatment research and clinical practice, and have indicated that EBT implementation is a priority. However, little empirical evidence exists regarding how effective specific, commonly used training models are in changing clinician behavior, achieving full implementation (e.g., increasing treatment fidelity, integrating into service settings), and supporting positive client outcomes. This novel application will evaluate the effectiveness of three training models (Learning Collaborative, Train-the-Trainer, and Web-Supported Self-Study) to implement a well-established EBT in real-world, community settings. To accomplish this goal, the project will be guided by three specific aims: 1) to build knowledge about training outcomes, 2) to build knowledge about implementation outcomes, and 3) to understand the impact of training clinicians using LC, TTT, and SS models on key client outcomes. Seventy-two of 243 possible (30%) licensed psychiatric clinics across Pennsylvania will be randomized to one of three training conditions: 1) Learning Collaborative (LC), 2) Train-the-Trainer (TTT), or 3) Web-Supported Self-Study (SS). Data also will be collected on staff trained by clinicians in the TTT group given that the intention of a TTT model is for participants of that group to return to their organization and train others within the organization. The impact of training (clinician level) wil be evaluated at 4 time-points coinciding with the training schedule: baseline, 6- (mid), 12- (post) and 24-months (1 year follow-up). Immediately after training begins, parent-child dyads (client level) will be recruited from the caseloads of participating clinicians (N = 288). Client outcomes will be assessed at four time points (pre-treatment, 1-month, 3-months, and 6-months after the pre-treatment). Implementation outcomes (clinic level) will be assessed at baseline, 6- (mid), 12- (post), and 24-months (1 year follow-up). This proposal builds on an ongoing state-led initiative to implement, and ultimately sustain, PCIT statewide. A team of diverse stakeholders including state policy makers, payers, consumers, service providers, and academics from diverse, but complementary areas (e.g., public health, social work, psychiatry), has been assembled to guide the research plan by incorporating input from multidimensional perspective. Lessons learned from this project will directly impact future EBT implementation efforts in Pennsylvania and other states, helping to increase the use of EBTs in community settings nationwide.